Marketers using SMS text messaging in their campaigns face new guidelines from the industry watchdog.
The Advertising Standards Authority says marketers must have recipients' consent before sending text messages. Additionally, they must reveal their identity and be transparent about promotional offers in SMS messages.
"It is important that marketers targeting consumers via their mobile phones conduct their business responsibly in this very personal marketing medium," said Andrew Brown, who is responsible for the authority's code of practice.
The move is a result of increased consumer dissatisfaction with marketers who regard mobile phone campaigns as an easy way of establishing one-to-one contact.
Complaints about SMS ads rose from 65 in 2002 to 393 last year.
Data sourced from: mad.co.uk; additional content by WARC staff